Nanofiltration separation has become a popular technique for removing largeorganic molecules and inorganic substances from water. It is achieved by a combination of threemechanisms: electrostatic repulsion, sieving an...Nanofiltration separation has become a popular technique for removing largeorganic molecules and inorganic substances from water. It is achieved by a combination of threemechanisms: electrostatic repulsion, sieving and diffusion. In the present work, a model based onirreversible thermodynamics is extended and used to estimate rejection of inorganic salts andorganic substances. Binary systems are modeled, where the feed contains an ion that is much lesspermeable to the membrane as compared with the other ion. The two model parameters are estimated byfitting the model to the experimental data. Variation of these parameters with the composition ofthe feed is described by an empirical correlation. This work attempts to describe transport throughthe nanofiltration membranes by a simple model.展开更多
Micro-filtration membrane （1.2 μm）, hyper-filtration membrane （0.45 μm） and nano-filtration membrane （1000 Dalton） were used to characterize the particle size distribution of the organic matters in effluent le...Micro-filtration membrane （1.2 μm）, hyper-filtration membrane （0.45 μm） and nano-filtration membrane （1000 Dalton） were used to characterize the particle size distribution of the organic matters in effluent leachate treated by the aged-refuse-bioreactor（ARB） installed at Laogang Refuse Landfill, Shanghai. The results showed that the particle size distribution of the treated fresh and aged leachate using the ARB were quite consistent. The organic matter with particle size below 1000 Dalton accounted for about 90%, balanced with the suspended （〉1.2 μm） and colloidal （1000 Dalton-l.2μm） matters. Hence, it is proposed that coagulation, nano-filtration and electrically chemical oxidation may be not applicable for the advanced treatment for the effluents to reach the discharge standard limit value defined in Chinese national Standard for Pollution Control on the Landfill Site of Municipal Solid Wastes （GB16889-2008）, CODCr〈100 mg/L. Aged refuse bioreactor combined reverse osmosis was suggested as an economically and technically feasible technology to treat sanitary landfill leachate.展开更多
Long-term air contamination and pollution challenges in particulate matter(PM) have raised fervent concerns for public health, e.g., the PM physical damage or the bacteria and virus carried by the PM. The desired air ...Long-term air contamination and pollution challenges in particulate matter(PM) have raised fervent concerns for public health, e.g., the PM physical damage or the bacteria and virus carried by the PM. The desired air filter, seeking both high filtration efficiency and low pressure drop remains challenging. Here, we report a bio-inspired spindle-knot halloysite nanotube microsphere-incorporated nanofiber(HNM-NF) filter with the assembly and shape structures of the spider silk. The resulting HNM-NFs exhibit integrated properties of high surface energy, hydrophilicity and strong PM capture. The spindle-knot structures could shrink the outer pore size on two-dimensional(2 D) surface and construct the fluffy 3 D reticular architecture, facilitating high-efficiency air pollutant capture(>85.0%) while maintaining low resistance to airflow(~39 Pa). The spindle-knot construction method was applicable to various materials(i.e.,Al_(2)O_(3), ZnO and TiO_(2)) and volume production of the microsphere-incorporated NF cartridge. The diversified spindleknot construction will be valuable for adapting to meet different filtration requirements.展开更多
文摘Nanofiltration separation has become a popular technique for removing largeorganic molecules and inorganic substances from water. It is achieved by a combination of threemechanisms: electrostatic repulsion, sieving and diffusion. In the present work, a model based onirreversible thermodynamics is extended and used to estimate rejection of inorganic salts andorganic substances. Binary systems are modeled, where the feed contains an ion that is much lesspermeable to the membrane as compared with the other ion. The two model parameters are estimated byfitting the model to the experimental data. Variation of these parameters with the composition ofthe feed is described by an empirical correlation. This work attempts to describe transport throughthe nanofiltration membranes by a simple model.
基金Acknowledgments： This work was financially supported by Science and Technology Support Plan of The Ministry of Science and Technology of People＇s Republic of China （No. 2006BAC02A19） China National Natural Science Foundation with Grant （No. 20177014）.
文摘Micro-filtration membrane （1.2 μm）, hyper-filtration membrane （0.45 μm） and nano-filtration membrane （1000 Dalton） were used to characterize the particle size distribution of the organic matters in effluent leachate treated by the aged-refuse-bioreactor（ARB） installed at Laogang Refuse Landfill, Shanghai. The results showed that the particle size distribution of the treated fresh and aged leachate using the ARB were quite consistent. The organic matter with particle size below 1000 Dalton accounted for about 90%, balanced with the suspended （〉1.2 μm） and colloidal （1000 Dalton-l.2μm） matters. Hence, it is proposed that coagulation, nano-filtration and electrically chemical oxidation may be not applicable for the advanced treatment for the effluents to reach the discharge standard limit value defined in Chinese national Standard for Pollution Control on the Landfill Site of Municipal Solid Wastes （GB16889-2008）, CODCr〈100 mg/L. Aged refuse bioreactor combined reverse osmosis was suggested as an economically and technically feasible technology to treat sanitary landfill leachate.
基金supported by the National Natural Science Foundation of China (21878341,51804343,41572036 and 51225403)the Natural Science Foundation of Hunan Province(2018JJ3670)the Key R&D Program of Hunan Province(2017GK2251)。
文摘Long-term air contamination and pollution challenges in particulate matter(PM) have raised fervent concerns for public health, e.g., the PM physical damage or the bacteria and virus carried by the PM. The desired air filter, seeking both high filtration efficiency and low pressure drop remains challenging. Here, we report a bio-inspired spindle-knot halloysite nanotube microsphere-incorporated nanofiber(HNM-NF) filter with the assembly and shape structures of the spider silk. The resulting HNM-NFs exhibit integrated properties of high surface energy, hydrophilicity and strong PM capture. The spindle-knot structures could shrink the outer pore size on two-dimensional(2 D) surface and construct the fluffy 3 D reticular architecture, facilitating high-efficiency air pollutant capture(>85.0%) while maintaining low resistance to airflow(~39 Pa). The spindle-knot construction method was applicable to various materials(i.e.,Al_(2)O_(3), ZnO and TiO_(2)) and volume production of the microsphere-incorporated NF cartridge. The diversified spindleknot construction will be valuable for adapting to meet different filtration requirements.
